Infrared heat lamps and/or electric heat mats are often used by swine producers to provide supplemental heat to young and newly born piglets. Supplemental heat is required for young piglets because they lack the necessary thermal insulation and the ability to manage their body temperature. Without supplemental heat, the piglets would obtain the necessary warmth from the sow. However, because sows can often trample or lay upon piglets, it is desirable to provide the supplemental needed to warm the piglets using artificial heating devices.
The supplementary heat is localized to a small area, thereby creating for the piglets a comfortable microenvironment within a larger farrowing room. Providing localized heat is preferred over large area heating because of the reduction in energy consumption, improved air quality, and ability to maintain a cooler room temperature, which is more appropriate for the lactating sows.
As newborn piglets grow their need for supplemental heat is reduced, allowing for the gradual reduction of supplemental heat during the first 2–3 weeks following birth. Various manual and semiautomatic methods have been devised for reducing this heat, including: raising up the heat lamps by means of a chain, a rheostat control for manual power adjustment, on/off thermostats, timers, high/low power switches, unplugging the heat lamp and using circuit breakers or toggle switches for manual on/off control. There are also a number of electronic controls having variable output power capability that can, to a limited degree, and at considerable expense, provide a means to automatically adjust the heat output to match the needs of the piglet.
Thermostats, timers and various other types of on/off switching devices lack the ability to modulate the power to the heating device, often resulting in a too hot or too cold condition that causes discomfort to the piglet, affecting the health of the animal, and it's ability to efficiently convert feed to weight gain.
Rheostats and similar manually adjusted devices lack the ability to dynamically adjust the heater's output in response to changing room temperatures and the reduced heat requirement of a growing piglet. Again, this often results in a too little or too much heat being applied to the microenvironment as the room temperature fluctuates due to seasonal and weather conditions beyond the producer's control. For example, a hot summer day can result in a gradual heating of the room to the extent that supplemental heat is not required for the young piglets. But as the nighttime air cools the room, the need for supplemental heat is again required. Attempting to manually adjust the supplemental heat to match the changing conditions becomes a 24-hour a day management problem.
Some of a current generation of sophisticated electronic controls do have the capability of adjusting the output of heating devices based on temperature and animal age. These controls measure the temperature within the microenvironment near the heating device and regulate the output thereof based on a desired microenvironment temperature, using a closed loop control algorithm. However, from a practical standpoint, these controls are not able to reliably control the large number of heating devices found in a typical animal confinement building. These controls have failed to achieve widespread appeal and success due in part to their high purchase and installation costs. In addition, the skill required to properly setup, operate, maintain, and troubleshoot these complex controls is also a major factor. Other, simpler and less expensive controls have sprung up to compete with their relatively more complex brethren, but are also limited by their limited capability and high installation costs.
The present invention is therefore directed to the following objectives: to provide energy savings through automatic reduction of the heating power applied to heating devices as piglets age; to provide energy savings through the automatic reduction of heating power applied to heating devices as the temperature of the farrowing room where the piglets are kept rises; to obviate the need to manually adjust lamp heights or to manually reduce power; to create an improved heated microenvironment for the piglets to result in healthier and more productive piglets; to reduce potential for heat stress to the sows by minimizing the heat added to the larger environment of the farrowing room; to extend the useful life of the heating devices used by providing a soft start feature; to eliminate lamp inrush current so that lamps run cooler at reduced power levels; to reduce peak demand from backup generators or power utilities; and, to reduce piglet mortality due to crushing by maintaining a comfortable microenvironment that allows young piglets to keep away from the sow. In addition to its use in farrowing operations, it is to be understood that the present invention is susceptible of use in agricultural, zoological and home settings with myriad animals, including but not limited to, birds such as chickens and turkeys, dogs, and cats.
These and other objectives and advantages of the invention will appear more fully from the following description, made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views.